Fake/multiple MX records on Hostmonster...

[ktn]

It appears that HostMonster will let you set up multiple MX records for my domain. I read _here (http://wiki.apache.org/spamassassin/OtherTricks)_ about setting up some fake MX records as a strategy for reducing spam.

I have already heavily edited my spamassassin user_prefs in HM, but because of lack of expertise have stopped short of implementing MooreDan's SA solution he shared in this thread (http://www.hostmonsterforum.com/showthread.php?t=2364).

So my question is, has anyone tried adding fake MX records on hostmonster (or anywhere else) and do you recommend this strategy or dis-recommend it?

Thanks.

[shadmego]

An MX (Mail eXchange) record is simply a record that points to the location where email is to be sent for certain domains. For instance, if I wanted to use Google Apps to manage my domain's email addresses, I would change my domain's MX record to point to Google Apps. Then to check my email, I would log onto Google Apps, or point my email client to Google Apps to download my email.

In essence, using fake MX records will eliminate the ability to use that domain for email. That means you won't be able to send or receive valid email. However, the article you point to indicates you would use fake MX along with your real MX entry, putting the real one in the middle.

While this would seem to work in theory, I would be leary of losing emails from valid clients or running in to large delays in receiving emails. I know the article says there is little delay and no missed emails, but I would still be cautious.

What I might recommend is to set up a subdomain and test this idea out there. Create emails for that subdomain (email1@sub.domain.com, email2@sub.domain.com, etc) and create your fake MX entries for that subdomain, leaving your main domain untouched. If your tests return positive results, you can impliment this solution on your main domain. If negative results, you haven't hurt your email traffic.

~regards

[ktn]

Thanks shadmego. Excellent advice. I've setup a subdomain called mail2.***.com. Now my next question is, how do I set this subdomain up (on hostmonster) to start handling email?

I know it's a linux newbie question, but I have SSH access (I know, newbie with SSH access = danger!), and if anyone could even just throw me a bone to chew on, I'm pretty good at learning if I know what direction to start in.

[shadmego]

There shouldn't be anything you have to do to "set it up". Just create your email accounts for that domain and to check the email, point your browser to:

mail2.yourdomain.com/webmail.

You can even point it to your main domain: yourdomain.com/webmail, and use the email address associated with the subdomain as the login name.

Does that make sense?

[ktn]

OK. I see now. I now have a choice of domains when setting up email accounts in cPanel.

However, I'm beginning to realize that this defeats the point of the article I mentioned. The whole point of having a fake or closed domain as my top priority mx record (and have my real mail server domain listed below it) was in hopes of causing spam servers to give up after failing the first MX record check. But if I've created a REAL alternate subdomain to be my first MX record, it doesn't discourage any spam at all.

I may have to try something else...
Thanks for your help.

[shadmego]

I think there is confusion.

What you are doing is setting up a test mail server (mail.sub.domain.com) which is seperate from mail.yourdomain.com. You can add MX entries for either/or/both mail servers and they will be independant of each other.

If you play with the MX entries of the subdomain's mail server, you can test whether or not real emails get through with minimal delay, or get lost altogether because of the fake MX entries. Based on those tests, you can then create your fake records for your real domain, knowning that you won't be losing *most* emails. I say most because it is impossible to know how all mail servers are configured.

I recommended this test because it would allow you to verify for yourself if the fake MX records work as advertised while not affecting any real email traffic to/from your site.

[ktn]

Yes, it would not be hard for me to get confused.

I see now (also) that I can set up my MX records for both my domain AND my newly created subdomain. But I still don't understand how I would generate the traffic I need on the new subdomain mail server to analyze whether or not it stops spam, or blocks legitimate traffic.

[shadmego]

The best way to do this would be to tell your friends and family that you will be using that new (subdomain) email address. Ask them to copy every email they send to the new address.

You can also post that address in plain site on your website, or another public-facing page for the spammers to grab. That way you can test if the fake MX records will be send elsewhere.

~regards